There is probably nothing illegal about this but I can see how servicemembers could get inappropriately slimed by this website:
Canadian troops are being warned against posting on Rank My Sarge, a website that allows users to anonymously rank soldiers they work with.
According to OTTAWA CITIZEN, “An email sent Oct. 28 by Brig.-Gen. Karl McQuillan, chief of staff of land operations at the army’s Ottawa headquarters, takes issue with the website Rank My Sarge, which he says is hosted anonymously on an American-based server.”
“Rank My Sarge is the first Anonymous Military Rating site,” the website claims.
But it appears the website does more to demean soldiers than it does to honestly and constructively rate them.
A message at the top of the site reads:
Anonymously insult or compliment your fellow soldier. Award them a medal for being a brown noser, having a hot wife, or simply for having a stupid mustache!” – Sgt. Slander. [Milblogging.com]
You can read more at the link.